Added Ephemeral Elliptic Curve Diffie Hellman ciphersuites to SSL/TLS
Made all modifications to include Ephemeral Elliptic Curve Diffie
Hellman ciphersuites into the existing SSL/TLS modules. All basic
handling of the ECDHE-ciphersuites (TLS_ECDHE_RSA_WITH_NULL_SHA,
TLS_ECDHE_RSA_WITH_RC4_128_SHA, TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA,
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA, TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA)
has been included.
diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index c426fa8..68c06cc 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -47,6 +47,10 @@
time_t t;
unsigned char sig_alg_list[20];
size_t sig_alg_len = 0;
+#if defined(POLARSSL_ECDH_C)
+ unsigned char elliptic_curve_list[20];
+ size_t elliptic_curve_len = 0;
+#endif
SSL_DEBUG_MSG( 2, ( "=> write client hello" ) );
@@ -203,6 +207,26 @@
ext_len += 6 + sig_alg_len;
}
+#if defined(POLARSSL_ECDH_C)
+ SSL_DEBUG_MSG( 3, ( "client hello, prepping for supported elliptic curves extension" ) );
+
+ elliptic_curve_list[elliptic_curve_len++] = 0x00;
+ elliptic_curve_list[elliptic_curve_len++] = POLARSSL_ECP_DP_SECP521R1;
+ elliptic_curve_list[elliptic_curve_len++] = 0x00;
+ elliptic_curve_list[elliptic_curve_len++] = POLARSSL_ECP_DP_SECP384R1;
+ elliptic_curve_list[elliptic_curve_len++] = 0x00;
+ elliptic_curve_list[elliptic_curve_len++] = POLARSSL_ECP_DP_SECP256R1;
+ elliptic_curve_list[elliptic_curve_len++] = 0x00;
+ elliptic_curve_list[elliptic_curve_len++] = POLARSSL_ECP_DP_SECP224R1;
+ elliptic_curve_list[elliptic_curve_len++] = 0x00;
+ elliptic_curve_list[elliptic_curve_len++] = POLARSSL_ECP_DP_SECP192R1;
+
+ ext_len += 6 + elliptic_curve_len;
+
+ SSL_DEBUG_MSG( 3, ( "client hello, prepping for supported point formats extension" ) );
+ ext_len += 7;
+#endif
+
SSL_DEBUG_MSG( 3, ( "client hello, total extension length: %d",
ext_len ) );
@@ -302,6 +326,35 @@
p += sig_alg_len;
}
+#if defined(POLARSSL_ECDH_C)
+ SSL_DEBUG_MSG( 3, ( "client hello, adding supported_elliptic_curves extension" ) );
+
+ *p++ = (unsigned char)( ( TLS_EXT_SUPPORTED_ELLIPTIC_CURVES >> 8 ) & 0xFF );
+ *p++ = (unsigned char)( ( TLS_EXT_SUPPORTED_ELLIPTIC_CURVES ) & 0xFF );
+
+ *p++ = (unsigned char)( ( ( elliptic_curve_len + 2 ) >> 8 ) & 0xFF );
+ *p++ = (unsigned char)( ( ( elliptic_curve_len + 2 ) ) & 0xFF );
+
+ *p++ = (unsigned char)( ( ( elliptic_curve_len ) >> 8 ) & 0xFF );
+ *p++ = (unsigned char)( ( ( elliptic_curve_len ) ) & 0xFF );
+
+ memcpy( p, elliptic_curve_list, elliptic_curve_len );
+
+ p+= elliptic_curve_len;
+
+ SSL_DEBUG_MSG( 3, ( "client hello, adding supported_point_formats extension" ) );
+
+ *p++ = (unsigned char)( ( TLS_EXT_SUPPORTED_POINT_FORMATS >> 8 ) & 0xFF );
+ *p++ = (unsigned char)( ( TLS_EXT_SUPPORTED_POINT_FORMATS ) & 0xFF );
+
+ *p++ = 0x00;
+ *p++ = 3;
+
+ *p++ = 2;
+ *p++ = POLARSSL_ECP_PF_COMPRESSED;
+ *p++ = POLARSSL_ECP_PF_UNCOMPRESSED;
+#endif
+
ssl->out_msglen = p - buf;
ssl->out_msgtype = SSL_MSG_HANDSHAKE;
ssl->out_msg[0] = SSL_HS_CLIENT_HELLO;
@@ -472,8 +525,8 @@
/*
* Initialize update checksum functions
*/
- ssl_optimize_checksum( ssl, i );
ssl->transform_negotiate->ciphersuite_info = ssl_ciphersuite_from_id( i );
+ ssl_optimize_checksum( ssl, ssl->transform_negotiate->ciphersuite_info );
if( ssl->transform_negotiate->ciphersuite_info == NULL )
{
@@ -629,9 +682,17 @@
return( 0 );
}
+#if !defined(POLARSSL_DHM_C) && !defined(POLARSSL_ECDH_C)
static int ssl_parse_server_key_exchange( ssl_context *ssl )
{
-#if defined(POLARSSL_DHM_C)
+ SSL_DEBUG_MSG( 2, ( "=> parse server key exchange" ) );
+ SSL_DEBUG_MSG( 2, ( "<= skip parse server key exchange" ) );
+ ssl->state++;
+ return( 0 );
+}
+#else
+static int ssl_parse_server_key_exchange( ssl_context *ssl )
+{
int ret;
size_t n;
unsigned char *p, *end;
@@ -640,22 +701,19 @@
sha1_context sha1;
int hash_id = SIG_RSA_RAW;
unsigned int hashlen = 0;
-#endif
+
+ const ssl_ciphersuite_t *ciphersuite_info = ssl->transform_negotiate->ciphersuite_info;
SSL_DEBUG_MSG( 2, ( "=> parse server key exchange" ) );
- if( ssl->transform_negotiate->ciphersuite_info->key_exchange !=
- POLARSSL_KEY_EXCHANGE_DHE_RSA )
+ if( ciphersuite_info->key_exchange != POLARSSL_KEY_EXCHANGE_DHE_RSA &&
+ ciphersuite_info->key_exchange != POLARSSL_KEY_EXCHANGE_ECDHE_RSA )
{
SSL_DEBUG_MSG( 2, ( "<= skip parse server key exchange" ) );
ssl->state++;
return( 0 );
}
-#if !defined(POLARSSL_DHM_C)
- SSL_DEBUG_MSG( 1, ( "support for dhm in not available" ) );
- return( POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE );
-#else
if( ( ret = ssl_read_record( ssl ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ssl_read_record", ret );
@@ -676,24 +734,55 @@
SSL_DEBUG_BUF( 3, "server key exchange", ssl->in_msg + 4, ssl->in_hslen - 4 );
- /*
- * Ephemeral DH parameters:
- *
- * struct {
- * opaque dh_p<1..2^16-1>;
- * opaque dh_g<1..2^16-1>;
- * opaque dh_Ys<1..2^16-1>;
- * } ServerDHParams;
- */
- p = ssl->in_msg + 4;
- end = ssl->in_msg + ssl->in_hslen;
-
- if( ( ret = dhm_read_params( &ssl->handshake->dhm_ctx, &p, end ) ) != 0 )
+#if defined(POLARSSL_DHM_C)
+ if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_RSA )
{
- SSL_DEBUG_MSG( 2, ( "DHM Read Params returned -0x%x", -ret ) );
- SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
- return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
+ /*
+ * Ephemeral DH parameters:
+ *
+ * struct {
+ * opaque dh_p<1..2^16-1>;
+ * opaque dh_g<1..2^16-1>;
+ * opaque dh_Ys<1..2^16-1>;
+ * } ServerDHParams;
+ */
+ p = ssl->in_msg + 4;
+ end = ssl->in_msg + ssl->in_hslen;
+
+ if( ( ret = dhm_read_params( &ssl->handshake->dhm_ctx, &p, end ) ) != 0 )
+ {
+ SSL_DEBUG_MSG( 2, ( "DHM Read Params returned -0x%x", -ret ) );
+ SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
+ }
}
+#endif /* POLARSSL_DHM_C */
+
+#if defined(POLARSSL_ECDH_C)
+ if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_RSA )
+ {
+ /*
+ * Ephemeral ECDH parameters:
+ *
+ * struct {
+ * ECParameters curve_params;
+ * ECPoint public;
+ * } ServerECDHParams;
+ */
+ ecdh_init( &ssl->handshake->ecdh_ctx );
+
+ p = ssl->in_msg + 4;
+ end = ssl->in_msg + ssl->in_hslen;
+
+ if( ( ret = ecdh_read_params( &ssl->handshake->ecdh_ctx,
+ (const unsigned char **) &p, end ) ) != 0 )
+ {
+ SSL_DEBUG_MSG( 2, ( "ECDH Read Params returned -0x%x", -ret ) );
+ SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
+ }
+ }
+#endif /* POLARSSL_ECDH_C */
if( ssl->minor_ver == SSL_MINOR_VERSION_3 )
{
@@ -759,15 +848,35 @@
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
- if( ssl->handshake->dhm_ctx.len < 64 || ssl->handshake->dhm_ctx.len > 512 )
+#if defined(POLARSSL_DHM_C)
+ if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_RSA )
{
- SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
- return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
- }
+ if( ssl->handshake->dhm_ctx.len < 64 ||
+ ssl->handshake->dhm_ctx.len > 512 )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad server key exchange message (DHM length)" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
+ }
- SSL_DEBUG_MPI( 3, "DHM: P ", &ssl->handshake->dhm_ctx.P );
- SSL_DEBUG_MPI( 3, "DHM: G ", &ssl->handshake->dhm_ctx.G );
- SSL_DEBUG_MPI( 3, "DHM: GY", &ssl->handshake->dhm_ctx.GY );
+ SSL_DEBUG_MPI( 3, "DHM: P ", &ssl->handshake->dhm_ctx.P );
+ SSL_DEBUG_MPI( 3, "DHM: G ", &ssl->handshake->dhm_ctx.G );
+ SSL_DEBUG_MPI( 3, "DHM: GY", &ssl->handshake->dhm_ctx.GY );
+ }
+#endif
+
+#if defined(POLARSSL_ECDH_C)
+ if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_RSA )
+ {
+ if( ssl->handshake->ecdh_ctx.grp.nbits < 163 ||
+ ssl->handshake->ecdh_ctx.grp.nbits > 521 )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad server key exchange message (ECDH length)" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
+ }
+
+ SSL_DEBUG_ECP( 3, "ECDH: Qp", &ssl->handshake->ecdh_ctx.Qp );
+ }
+#endif
if( ssl->minor_ver != SSL_MINOR_VERSION_3 )
{
@@ -885,8 +994,8 @@
SSL_DEBUG_MSG( 2, ( "<= parse server key exchange" ) );
return( 0 );
-#endif
}
+#endif /* POLARSSL_DHM_C || POLARSSL_ECDH_C */
static int ssl_parse_certificate_request( ssl_context *ssl )
{
@@ -1039,16 +1148,15 @@
{
int ret;
size_t i, n;
+#if defined(POLARSSL_DHM_C) || defined(POLARSSL_ECDH_C)
+ const ssl_ciphersuite_t *ciphersuite_info = ssl->transform_negotiate->ciphersuite_info;
+#endif
SSL_DEBUG_MSG( 2, ( "=> write client key exchange" ) );
- if( ssl->transform_negotiate->ciphersuite_info->key_exchange ==
- POLARSSL_KEY_EXCHANGE_DHE_RSA )
+#if defined(POLARSSL_DHM_C)
+ if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_RSA )
{
-#if !defined(POLARSSL_DHM_C)
- SSL_DEBUG_MSG( 1, ( "support for dhm in not available" ) );
- return( POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE );
-#else
/*
* DHM key exchange -- send G^X mod P
*/
@@ -1082,9 +1190,42 @@
}
SSL_DEBUG_MPI( 3, "DHM: K ", &ssl->handshake->dhm_ctx.K );
-#endif
}
else
+#endif /* POLARSSL_DHM_C */
+#if defined(POLARSSL_ECDH_C)
+ if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_RSA )
+ {
+ /*
+ * ECDH key exchange -- send client public value
+ */
+ i = 4;
+
+ ret = ecdh_make_public( &ssl->handshake->ecdh_ctx,
+ &n,
+ &ssl->out_msg[i], 1000,
+ ssl->f_rng, ssl->p_rng );
+ if( ret != 0 )
+ {
+ SSL_DEBUG_RET( 1, "ecdh_make_public", ret );
+ return( ret );
+ }
+
+ SSL_DEBUG_ECP( 3, "ECDH: Q", &ssl->handshake->ecdh_ctx.Q );
+
+ if( ( ret = ecdh_calc_secret( &ssl->handshake->ecdh_ctx,
+ &ssl->handshake->pmslen,
+ ssl->handshake->premaster,
+ POLARSSL_MPI_MAX_SIZE ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, "ecdh_calc_secret", ret );
+ return( ret );
+ }
+
+ SSL_DEBUG_MPI( 3, "ECDH: z", &ssl->handshake->ecdh_ctx.z );
+ }
+ else
+#endif /* POLARSSL_ECDH_C */
{
/*
* RSA key exchange -- send rsa_public(pkcs1 v1.5(premaster))
@@ -1206,8 +1347,8 @@
* Reason: Otherwise we should have running hashes for SHA512 and SHA224
* in order to satisfy 'weird' needs from the server side.
*/
- if( ssl->session_negotiate->ciphersuite == TLS_RSA_WITH_AES_256_GCM_SHA384 ||
- ssl->session_negotiate->ciphersuite == TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 )
+ if( ssl->transform_negotiate->ciphersuite_info->cipher ==
+ POLARSSL_CIPHER_AES_256_GCM )
{
hash_id = SIG_RSA_SHA384;
hashlen = 48;